Deficits in language skill can be severely limiting for an individual with an autism spectrum disorder, creating barriers in cognitive and social development and in long-term outcomes, such as the ability to live independently. This project directly addresses a critical problem in the study of autism spectrum disorders (ASD); heterogeneity in language functioning. We propose to study the neural response associated with perception of auditory and audiovisual speech in children with ASD. To do this, we will pair EEG/ERP and eye- tracking technology to collect perceptual data to identify biomarkers associated with language outcome. In addition, we will include a novel control group of children with disorders in spoken language. Children with disorders in spoken language share deficits in language with children with ASD, but do not exhibit primary deficits in social reciprocity. Thus, this comparison will allow us to tease apart the contribution of linguistic and social factors to problems in language functioning in children with ASD. Further, using a single-subject design, we will pilot a focused speech perception training to assess the efficacy of this approach for improving perception of auditory and audiovisual speech in children with ASD. Identifying the underlying biomarkers of speech perception will significantly further our scientific knowledge about the causes of language deficits in ASD and contribute to the objectives of the IACC Strategic Plan for ASD Research by targeting identification of biomarkers in language functioning for affected individuals across the autism spectrum. Specifically, this work will 1) address how speech processing correlates with the range of language functioning in ASD (heterogeneity), 2) lead to development of a tool that may result in early identification of children with ASD at greatest risk for significant language deficits (earlier detection) and 3) evaluate an intervention explicitly designed to train auditory and audiovisual perceptual skills in children with ASD (development of targeted interventions).